Polyester filaments having an improved water-absorbing property

ABSTRACT

POLYESTER FILAMENTS CONTAINING THEREIN 0.4-5% BY WEIGHT OF A POLYALKYLENE ETHER AND 0.3-3% BY WEIGHT OF A METAL SALT DERIVATIVE, AND HAVING FINE PORES ALIGNED IN THE DIRECTION OF THE FILAMENT AXIS.

Aug. 8, 1972 KElZO SANO ETA!- 3.532.346

POLYESTER FILAMENTS HAVING AN IMPROVED WATER'ABSORBING PROPERTY Filed Oct. 27, 1969 4 Sheets-Sheet 1 FIG.I FIG.2

FIG.3 FIG.4

Aug; 8 1972 zo SANQ ETAL 3,682,846

POLYESTER FILAMENTS HAVING AN IMPROVED WATER-ABSORBING PROPERTY Filed Oct. 2'7, 1969 4 Sheets-Sheet 2 A t- 1-972 KEIZO SANO TA POLYESTER FILAMENTS HAVING AN IMPROVED WATER-ABSORBING PROPERTY 4 Sheets-Sheet 5 Filed 06t- 27, 1969 FIG.9

FIG

FIG

z- 8, 1912 KEIZO SANO AL 3,682,846

POLYESTER FILAMENTS HAVING AN IMPROVED WATER-ABSORBING PROPERTY Filed Oct. 27, 1969 4 Sheets-Sheet &

United States Patent U.S. Cl. 260-25 N 9 Claims ABSTRACT OF THE DISCLOSURE Polyester filaments containing therein 0.4-S by weight of a polyalkylene ether and 0.3-3% by weight of a metal salt derivative, and having fine pores aligned in the direction of the filament axis.

This invention relates to polyester filaments having an improved water-absorbing property which is not degraded by repetition of washing. More specifically, it relates to polyester filaments containing 0.4 to 5% by weight of a polyalkylene ether and 0.3 to 3% by weight of a metal salt derivative and having fine pores aligned in the direction of the filament axis.

The conventional techniques for imparting a water-absorbing property to polyester filaments will be described below.

(A) Attempts to render polyester filaments hydrophilic by copolymerizing a polyester with a polyether compound have been proposed in Japanese patent application publications Nos. 10,336/61, 4,312/64 and 15,095/63, British Patent No. 682,866 specification, and US. Patent No. 2,744,087 specification.

However, in accordance with methods proposed in these references it is difiicult to impart a suflicient water-absorbing property to polyester filaments without deterioration of their thermal and mechanical properties.

(B) Methods comprising blending a polyether in the dispersed state into a polyester have been known from Japanese patent application publications Nos. 5,214/64 and 14,613/66. However, in accordance with these known methods it is impossible to impart a sufiicient water-absorbing property to polyester filaments without deterioration of their thermal and mechanical properties.

(C) A method comprising blending a ring-containing vinyl polymer in a polyester and eluting the blended polymer to thereby form fine pores in the polyester has been known from Japanese patent application publication No. 4,815/66.

However, this method fails to impart a water-absorbing property to polyesters.

(D) In view of the description of Example 2 of the specification of Japanese patent application publication No. 5,214/64 it is presumed that there was obtained a fibrous composition of a polyester containing a polyethylene glycol and having fine pores. In accordance with the teachings of this reference it is possible to impart to polyester filaments a temporary water-absorbing property but the said water-absorping property is abruptly degraded by repetition of washing. Therefore, the filaments obtained in accordance with the teachings of this reference are of little utility.

(E) A method comprising making a polyalkylene ether and an alkali metal sulfonate derivative present in a polyester has been known from Italian Patent No. 796,237 specification. However, in accordance with this method it is impossible to impart a water-absorbing property to polyester filaments.

3,682,846 Patented Aug. 8, 1972 As results of our researches made with a view to overcoming defects of these prior arts, particularly shortcomings that a suflicient water-absorbing property cannot be imparted to polyester filaments, an attempt to impart a sufiicient water-absorbing property to polyester filaments results in deterioration of their thermal and mechanical properties, and that if a water-absorption property is once imparted to polyester filaments, said property is not sufficiently resistant to washing, we arrived at the present invention. Accordingly, a primary object of this invention is to impart to polyester filaments an everlasting and Sllfr ficient waterabsorbing property without deterioration of their thermal and mechanical properties.

This object of the present invention can be attained by polyester filaments containing 0.4-5% by Weight of a polyalkylene ether and 0.3-3% by weight of a metal salt derivative .and having fine pores aligned in the direction of the filaments axis.

The polyester referred to in this invention is a polyester in which at least 60% of the recurring units is composed of polyethylene terephthalate. For instance, it includes polyethylene terephthalate; copolymers obtained by copolymerizing polyethylene terephthalate with a known dicarboxylic acid component, dihydroxy component or hydroxycarboxylic acid component; polyester blends obtained by melt mixing an ethylene terephthalate homopolymer or copolymer with other homopolyester or copolyester; copolymers comprising an ethylene terephthalate homopolymer or copolymer and containing therein amide, urethane, ether, carbonate or other linkages; a fiber-forming polyester other than polyethylene terephthalate; and a fiber-forming polyester ether.

Of course, the above cited polymers may contain known catalysts, coloration inhibitors, heat stabilizers, antistatic agents, optical whitening agents, antiflaming agents, dyestuffs, pigments and inactive fine particles.

The polyalkylene ether referred to in this invention is a polymer whose main chain is composed chiefly of alkylene ether units. For instance, it includes polyethylene oxide, polypropylene oxide, an ethylene oxide-propylene oxide copolymer, a mixture of polyethylene oxide and polypropylene oxide, a polymer derived from tetrahydrofuran, and a polymer derived from 1,3 dioxane. These polymers may have a group OH, -OR or OCO--R (in which R is a monovalent organic group which may be optionally substituted) as the terminal group. Two or more of these terminal groups may be present in the polymer. In addition, a polymer blocked with phosphoric acid or a phosphate may be advantageously used. However, it is not preferable to use a modified polyalkylene ether which is made completely inactive by converting all the terminal groups to OR groups.

It is preferable that the polyalkylene ether has a num-' ber average molecular weight exceeding 4,000. The use of a polyalkylene ether having too low a molecular weight is not preferred because a blend of the polyester and such a low molecular weight polyalkylene ether is inferior in spinnability and drawability.

Of course, the polyalkylene ether may contain known oxidants, catalysts and other additives. I

The blending of the polyalkylene ether into the polyester may be performed by any method. For instance, it is possible to add a polyalkylene ether to a polymerization vessel for polyester at the time of initiation of the polymerization, during the polymerization or after completion of the polymerization. It is also possible to blend a polyalkylene ether with the use of an extruder into a polyester pelletized after completion of the polymerization. Further, it is possible to mix a solid polyester with a polyalkylene ether by means of a blender and then melt spin the mixture. Still further, it is possible to melt a polyester and a polyalkylene ether separately and mix the melts by means of a screw just prior to the spinning. In order to attain the object of the present invention it is most preferable to add a polyalkylene ether to a polymerization vessel for the preparation of a polyester after completion of the polymerization, or to melt a polyalkylene ether and a polyester separately and mix the melts with the use of a screw just prior to the spinning.

The metal salt derivative referred to in this invention includes derivatives of alkali metal sulfonates, derivatives of metal salts of carboxylic, phosphonic and sulfinic acids, and derivatives of dior mono-metal salts of phosphoric and phosphorous acids.

These metal salts will be detailed hereinbelow.

The alkali metal sulfonate derivative referred to in this invention includes compounds having a so-called surface-activating property, more specifically compounds having a hydrophobic group other than the sulfonic group. It is especially preferable to use a compound having only one sulfonic group at one end of its molecule.

Typical instances of such derivative are sodium dodecylbenzenesulfonate, potassium dodecylbenzenesulfonate, sodium nonylbenzenesulfonate and sodium 3-nonylphenoxypropanesulfonate. But, the derivative is not limited to these specifically mentioned salts. It is not preferred to use an alkali metal sulfonate derivative having two or more sulfonic groups in the molecule, because such compound is not well blended with a polyester and resulting filaments are likely to have poor properties.

The metal salt derivative of a carboxylic, phosphonic or sulfinic acid includes surface-activating compounds containing in the molecule at least one hydropholic group (which corresponds-to the metal salt portion of an acid such as carboxylic acid) and a suitable hydrophobic group such as an alkyl group.

As such salt derivative there are cited following compounds but it is not limited to these specifically exemplified compounds:

( CaHnCOONa.

( (331127 O O K C mHavCOON 8.

(4) C12Hz5-O-CH2C O 0N3 (6) O i nHza- -ONa PONa (BN8. 0

i -o QA I 0 l C12 25 O K 03H" COO /Zn 0 H" C 00 CoHm- -O NaO-P ONaNaOPO-Na (ll) i2H25 8 These metal salt derivatives should not possess an ester-linkage-forming group. In case a metal salt derivative containing an ester-linkage-forming group is used, the water-absorbing property of the resulting polyester filaments is very low, and it tends to impose bad influences on properties of the polyester filaments.

So-called surface-activating compounds having in the molecule at least one hydrophilic group (corresponding to the metal salt portion of an acid) and a hydrophobic group such as an alkyl group are preferably used in the present invention as the dior mono-metal salt of phosphoric or phosphorous acid.

Such compounds are used in the form of a monoor di-metal salt, and those in which the remaining -OH groups of phosphoric or phosphorous acid are converted to alkylatyl ester forms are preferably used. Further, it is preferable to use compounds which are free of esterlinkage-forming groups such as an acid group or hydroxyl group other than the phosphoric acid ester portion. The reason is that such ester-linkage-forming group reacts with a polyester when the monoor di-metal salt derivative of phosphoric or phosphorous acid is blended into the polyester, resulting in occurrence of an undesirable modification of the polyester.

Compounds having the following structures may be applied to this invention, but the monoor di-metal salt derivative of the phosphoric or phosphorous acid is not limited to these specificaly mentioned examples in the present invention.

ONa

The blending of the above mentioned metal salt derivative may be performed by any method. It is possible to blend the metal salt derivative into the polyester either together with a polyal'kylene ether or separately. The

blending may be carried out before the initiation of the polymerization for the preparation of a polyester, during the polymerization, or after completion of the polymeri zation. The salt derivative may be added to a polymerization vessel or blended by means of an extruder or blender. It is also possible to conduct the blending of the metal salt derivative just prior to the spinning. In the case of a monoor di-metal salt derivative of phosphoric or phosphorous acid, it is preferable to blend it into the polyester after completion of the polymerization.

The present invention will be detailed by referring to drawings.

FIG. 1 is a microscopic photo illustrating the side of filaments from a blend obtained by incorporating polyethylene glycol into polyethylene terephthalate containing sodium dodecylbenzenesulfonate. The figure illustrates the stage that the polyethylene glycol is aligned in the polyethylene terephthalate along the filament axis. Since the filaments have not fine pores, they take a transparent appearance. FIG. 2 is a microscopic photo illustrating the side of filaments of this invention. As they have fine pores aligned along the filament axis, they possess a non-transparent appearance.

FIG. 3 is an electromicroscopic photo of the filaments of FIG. 1 after they have been dyed with osmium tetraoxide (OsOQand then dissolved. It is observed that the osmium tetraoxide is adsorbed in the polyether portion and that the polyether component is blended in the state extended in the direction of the filament axis.

FIG. 4 is an electromicroscopic photo of filaments of the present invention prepared by eluting the polyether portion from the filaments of FIG. 1, after they have been dyed with osmium tetraoxide and then dissolved. In this figure the stripe looks thinner because of the existence of fine interior pores than in FIG. 3.

FIG. 5 is a microscopic photo illustrating the side of polyester filaments from a blend obtained by incorporating polyethylene glycol into polyethylene terephthalate containing a di-sodium salt of nonylbenzenephosphonic acid. FIG. 6 is a microscopic photo illustrating the side of polyester filaments according to this invention.

FIG. 7 is an electromicroscopic photo of polyester filaments of FIG. 5, after they have been dyed with osmium tetraoxide and then dissolved. FIG. 8 is an electromicroscopic photo of polyester filaments of the present invention obtained by eluting the polyether portion from polyester filaments shown in FIG. 5, after they have been dyed with osmium tetraoxide and then dissolved.

FIG. 9 is a microscopic photo illustrating the side of polyester filaments incorporated with a di-sodium salt of nonylphenolphosphoric acid ester. FIG. 10 is a microscopic photo illustrating the side of polyester filaments of the present invention.

FIG. 11 is an electromicroscopic photo of filaments shown in FIG. 9, after they have been dyed with osmium tetraoxide and then dissolved. FIG. 12 is an electromicroscopic photo of polyester filaments of the present invention obtained by eluting the polyether portion from polyester filaments shown in FIG. 9, after they have been dyed with osmium tetraoxide and then dissolved.

The fine pores aligned in the direction of the filament axis referred to in the present invention indicate pores being present in the filament and having a diameter of 0.01 to 3p and a length-to-diameter ratio of at least 5.

As shown in FIGS. 2, 4, 6, 8, 10 and 12, the presence of fine pores is confirmed by observation under an optical microscope or electromicroscope. It is preferable that the ratio of the pore volume to the filament volume is within a range from 0.5 to 10%. In case the pore volume ratio is too small, the intended object of the present invention cannot be attained. On the other hand, in case the pore volume ratio is too great, the mechanical properties of the filaments are lowered.

The formation of fine pores may be performed by any method. For instance, itis possible to adopt a method comprising treating filaments with warm water or a dilute aqueous alkali solution to thereby elute a blended polyalkylene ether. By such treatment the amount of the polyalkylene ether blended into polyester filaments is decreased, and pores such as shown in FIGS. 2, 4, 6, 8, l0 and 12 are formed in the filaments. In case the amount of the polyalkylene ether is not decreased even by such treatment, the existence of pores such as shown in FIGS. 2, 4, 6, 8, 10 and 12 is not observed.

It is also possible to adopt a method blending into a polyester a polymer incompatible with the polyester such as polyamide and polyolefin in addition to a polyalkylene ether and a metal salt derivative and eluting the blended polymer from the blend with a solvent for said blended polymer.

It is most preferable to adopt a method comprising eluting a part of a blended polyalkylene ether with a dilute aqueous alkali solution, while leaving the remaining part of the polyalkylene ether in the filament-constituting material.

During the formation of fine pores a part of the metal salt derivative is necessary stripped oil from the filaments.

The amount of the polyalkylene ether finally contained in the filaments is within a range from 0.4 to 5% by weight, preferably from 1 to 4% by weight.

In case the amount of the polyalkylene ether is too small, the intended object of the present invention cannot be attained. On the other hand, in case the amount of the polyalkylene ether is too large, thermal and mechanical properties of the filaments are lowered.

The amount of the metal salt derivative finally contained in the filaments is within a range from 0.3 to 3% by weight, preferably from 0.3 to 2.5% by weight.

In case the amount of the metal salt derivative is too small, the intended object of the present invention cannot be attained. In case the amount of the metal salt derivative is too large, the mechanical properties of the filaments are degraded.

According to this invention there are provided polyester filaments having an excellent water-absorbing property and its excellent retainability. Reasons why such excellent effects are attained in accordance with the present invention have not been completely elucidated. Only blending of a polyalkylene ether and a metal salt derivative into filaments does not result in manifestation of any water-absorbing property. The synergistic action of fine pores and the polyalkylene ether and metal salt derivative contained in filaments produces the abovementioned effects.

Further, the filaments of this invention retain excellent physical properties inherent to polyester fibers and possess an excellent antistatic property at the same time.

This invention will be now detailed by referring to examples.

In examples the parts indicate parts by weight.

The analysis of the polyalkylene ether component was conducted in accordance with the method of Robert (Robert, J. Levins and Robert, M. Ikeda, Analy. Chem. 37, 671 (1965)) after decomposing the polymers with aminopropanol and neutralizing the same with acetic acid.

The analysis of the alkali metal sulfonate derivative was conducted by a method comprising depolymerizing the polymers with ethylene glycol, forming an aqueous solution of the depolymerized polymers, making the solution acidic with sulfuric acid, adding methylene blue thereto, extracting the resulting complex and subjecting it to colorimetric determination.

The amount incorporated of the derivative of a metal salt of a carboxylic, phosphonic or sulfinic acid was determined by the analysis of the metal content according to the atomic absorptiometric method.

The amount incorporated of the dior mono-metal salt of phosphoric or phosphorous acid was determined by the analysis of the metal content according to the atomic absorptiometric method.

The inherent viscosity of the polymer was measured in o-chlorophenol at 25 C.

The evaluation of physical properties of filaments was based on CR values of wooly-processed yarns. CR

8 The oozing water is absorbed in the sample 4 and then released into the air through the sample 4. In case the sample has an excellent water-absorbing property, the amount of water passing through the fine tube 1, water values are values indicating the crimp retainability of 5 pool 2, unglazed plate 3 and sample 4 should be great. the processed yarns. Higher values mean that yarns are Therefore, the amount consumed of water was read from more excellent in the crimp retainability and the bul'kithe scale on the fine tube 1, and based on the read value ness. The measurement of CR values is conducted in the the water-absorbing property was evaluated. In FIG. 13, following manner: the reference numeral 6 represents a water supply tank.

The sample is subjected to a boiling water treatment 10 FIG. 14 is a graph illustrating the results of the actual under a load of zero for 5 minutes. Then, the sample measurements made on several samples by employing is taken out from boiling water, thrown into water and the apparatus of FIG. 13. In FIG. 14, the ordinate deallowed to stand therein for 1 minute under a load of notes the amount consumed (cc.) of water and the 0.1 -g./d. The length (L of the sample was measured. abscission represents the time (minutes). Then, the sample was taken out from water and allowed 15 I p to stand under a load of 0.02 g./d. for 30 seconds. The EXAMPLE 1 AND COMPARATIVE EXAMPLE 1 length (1. of the sample was measured again. The CR Polyethylene terephthalate (-A) of an intrinsic visvalue of the sample was calculated by the following cosity of 0.660 obtained by a customary method was equation: weighed at 295 C. by a gear pump and then fed to a L kneading screw portion heated at 285 C. A 2:1 mix- GR Value= 00 ture (B) of polyethylene glycol having a number average 1 molecular weight of 20,000 and sodium dodecylbenzene- The heat resistance was evaluated based on changes in lf t was weighed at 5 Q by a gear pump and f d color of the sample when it was allowed to stand still in to the kneading screw portion heated at 285 C. a hot air drier maintained at 180 C. for 5 hours. 5 The mixing ratio of (A);(B) was 92 5;7 5 The The Coloration Was evaluated based on b Values measture was transferred from the kneading screw portion to y employing a yp color machine of Japan a spinneret portion while being kept in the molten state. C0101 Machine g P b Value means an Then, the mixture was spun at a rate of 30 g./min. increase in coloration in y through a spinneret having 36 holes of a diameter of a The evaluation of the water-absorbing property was 30 0,23 m. and taken up at a rate of 1000 m,/min to conducted in the following manner: obtain undrawn filaments. Then, the undrawn filaments The sample was allowed to Stand at and a were drawn at a draw ratio of 3.66 at a speed of 400 relative humidity Of 65% for 4 u Then, three m./min. by means of a hot pin maintained at 100 C. Sheets of the Sample were P P- Theffiafiel', 30 of The resulting drawn filaments were characterized by water was dropped onto the piled sheets and the period a fineness of 75.1 d., a strength of 4.8 g./d., an elongation f tim fr m h i it of the pp to the point of 27.2% and a boiling water shrinkage of 11.5%. when any reflecting light from the su face of Wa e hav- Two of the so obtained filaments were gathered toing expanded on the sample was not obs rv d (the t m gether and subjected to a wooly-processing at a yarn feed being called water absorption time) was measured. A rate of 49.8 m./min., and a take-up rate of 44.0 m./min. smaller value of the water absorption time means a 40 with the use of a spindle rotating at 175,000 rpm. and higher water-absorbing property of the sample. a hot plate maintained at 205 C. Thus, there was ob- The washing treatment was conducted in the following tained a wooly-processed yarn having a strength of 4.3 manner: g./d., an elongation of 31.5% and a CR value (crimp 15 liters of water at 40 C. was filled in a washing retaining property) of 35.6%. machine of an automatic reverser type of Toshiba ElCc- A knitted cloth of a weight of 15-18 10- gm./cm. tric Co. and 26 g. of an anionic, weakly alkaline soap was formed from the so obtained wooly-processed yarn. (Zab of Kao Soap Co.) was added thereto. The wash- Then, the knitted cloth was scoured at 80 C. for 20 ing was carried out for 15 minutes and the washed sample minutes under the conditions of a cleanser of 2 g./liter, was rinsed for 15 minutes in flowing clean water. soda'ash of 1 g./liter and a bath ratio of 1:100. Further,

FIG. 13 illustrates an apparatus in use for another the knitted cloth was treated with a 0.3 N aqueous soluevaluation of filaments. More specifically, the apparatus tion of sodium hydroxide at a bath ratio of 1:100 for 20 is used for evaluation of the water-absorbing property of minutes at the boiling point of the solution. Before and knitted products. In FIG. 13, the numerical reference 1 after the above alkali treatment, the weight decrease indicates a fine tube containing water therein, and the ratio, and the amounts of polyethylene glycol and sodium reference numeral 2 designates a water pool connected dodecylbenzene-sulfonate in the knitted cloth were measwith the fine tube 1. The numeral reference 3 indicates ured. The results are shown in Table 1 below.

TABLE 1 Amount of Weight Amount of sodium dodecrease polyethyldecylbenzeneratio, ene glycol, sulfonate, percent percent percent Comparative Example 1 (before alkali treatment)- 0 4. 9 2. 5 Example 1 (after alkali treatment) 8. 5 1. 8 1.1

an unglazed plate adhering closely to water, and the refer- Optical microscopic photos illustrating the sides of ence numeral 4 represents a knitted product sample on the drawn yarn before the scouring and alkali treatments which a perforated plate 5 formed of polymethyl methand of the drawn yarn after said treatments are shown acrylate is placed so as to regulate the form of the samin FIGS. 1 and 2. FIG. 3 is an electromicroscopic photo ple. Air is blown to the sample with an angle of 45 of the yarn of FIG. 1 after it has been dyed with osmium with respect to the sample surface at a rate of 0.5 m./sec. tetraoxide and then dissolved. FIG. 4 is an electromicroby means of an air blaster 6. The atmosphere'in maintained at 20 C. and a relative humidity of 65%. The water in the fine tube ,1 and the water pool 2 rises and oozes'out on the surface of the unglazed plate 3 in such scopic photo of the yarn of FIG. 2 after it has been dyed with osmium tetraoxide and then dissolved. From the results shown in Table l, and FIGS. 1 to 4 it is seen that in the yarn before the alkaline treatment the polya manner as if the sweat comes out from the human body. 7 ethylene glycol was incorporated in the form of stripes 9 10 and that a part of the polyethylene glycol corresponding to 3.1% of the total yarn was stripped off by the alkali EXAMPLE 2 AND COMPARATIVE treatment to form fine pores. It is also seen that in addi- EXAMPLES 2 TO 5 tion to the polyethylene glycol and sodium dodecylbenzenesulfonate, the polyethylene terephthalate per se was 5 These examples are given to show what phenomena stripped off in an amount of 4.0% by the alkali treatment are brought about by changing the amounts incorporated and hence, the yarn was made thinner and the pores were of polyethylene glycol and sodium dodecylbenzenesulexpanded from their interiors. From FIG. 4 it is also fonate in the polyester of Example I.

seen that the diameter of the pore was about 0.1a and The experiments were conducted in the same manner the length-to-diameter ratio was greater than 10. 10 as in Example 1 except changing the mixing ratio of poly- With respect to the knitted cloth of the yarn before ethylene glycol and sodium dodecylbenzenesulfonate, the

the alkali treatment and the knitted cloth of the yarn incorporation ratio of the mixture of polyethylene glycol after the alkali treatment, the water-absorbing property and sodium dodecylbenzenesulfonate to polyethylene was measured. The results are shown in Table 2 below. terephthalate, or the amounts of polyethylene glycol and TABLE 2 I Before washing After 1 washings After 50 washings From the results shown in Table 2 it is seen that even sodium dodecylbenzenesulfonate incorporated into the filaments containing polyethylene glycol and sodium polyester. The results are shown in Table below.

TABLE 5 Comparative Comparative Comparative Comparative Example 2 Example 3 Example 2 Example 4 Example 5 t incor orated of polyethylene glycol (percent).. 4 5.0. i 15.0 5.0- 5.0- 1.0, fir ri iin t incorgorated of sodinn dodeoylbenzene sulfonate (percent) 0 0 5 L0. Pro erties of wooly-proeesse yarn:

trength (g./d.) 4 5. r 3 9- 4.4- 3.8- 4.6.

Elongation (percent)- 30.6- 28.1- 81.2- 27.2- 32.0.

CR value (percent) 31-6. 3 30.6- 18.5- 31.8.

After alkali treatment:

Weight decrease ratio (percent). 7.1-

Amount of polyethylene glycol (percent). 2.1. 5.5- 1.9- 1.7- 1.0.

Amount of sodium ttlodecylbenzene suiionate (percent) 0 0 2.1- 4.2- 1.0. iie i i g $525152? Less than 1 Less than 1 Less than 1 Less than 1 2 seconds.

second. second. second. second.

0 washings 1 second. 1 second. ..'.'.'.....-.do ..d0 More than 10 minutes.

50 W1 hing I Y Y tirnln 4minutes...-. lsecond do D Heat resistance after alkali treatment (change in I) value) +1.9- +3.6. +2.1 +7.7

dodecylbenzenesulfonate cannot possess a water-absorb- From the results shown in Table 5 the following matters ing property unless they have fine pores therein. can be seen,

Table 3 shows the results of the measurement of the As i the case f comparative Example 2, the fil t heat resistance of the limited CIOthS 0f the Y containing polyethylene glycol and having pores therein the alkali treatment and 0f the y after the alkah but being free of sodium dodecylbenzenesulfonate are intreatmentferior in washing resistance of the water-absorbing prop- TABLE 3 H t r sistance erty. As in the case of Comparative Example 3, even if the 1 N (Chan 2 value) amount of polyethylene glycol is increased in Comparative EXamP e g Example 2, the washing resistance of the water-absorbing Comparatlve Example 1 (before alkah treatment) +2.0 property is not improved, and moreover the heat resistance Example 1 (after alkali treatment) +L8 and the CR value of the processed yarn are lowered. As

I in the case of Comparative Example 4, in case the amount For comparison Sake Properties of i j polyester of sodium dodecylbenzenesulfonate is too large, the CR filaments (control) wlthout addltlon of poly value of the processed yarn is low and the heat resistance ethylene glycol and i doilecylbenzenesulfoliate is degraded. As in Comparative Example 5, even if fila- Were exammed' The Spmmng drawmg wooly'processmg ments contain polyethylene glycol and sodium dodecyl- $3 25 ggi g g z g igi gz g $233 32: g g iigz benzenesulfonate and the weight decrease is observed after terized by a fineness of 749 d. a strength of 0 the alkali treatment, a sufficient water-absorbing property and elongation f 273% and a boiling water shrinkage is not imparted to the filaments when the weight decrease of 11.3%. The wooly-processed yarn was characterized 15 due only'to h Surface falllhg h P y y by a strength of 4.5 g./d., an elongation of 33.4% nd glycol contained in the form of stripes inside the filaments a CR value of 35.6%, and the weight decrease ratio by is not extracted. Thus, it is seen that the results given in the alkali treatment was 2.3%. The water-absorbing Table 5 demonstrate clearly the effects of the present property of the knitted cloth was as follows: invention.

TABLE 4 Before washing After 10 washings After 50 washings Before alkali treatment More than 10 minutes.-- More than 10 minutes..- More than 10 minutes. After alkali treatment. 5 minutes do.- Do.

The heat resistance expressed in terms of the change COMPARATIVE EXAMPLE 6 in I: value of the knitted was +1.5 either before or after This example is given to Show that a fli i t waterthe alkali treatment. absorbing property is not given to filaments containing only an alkali metal sulfonate derivative, filaments obtained by subjecting the above filaments to an alkaline treatment and filaments containing an alkali metal sulfonate derivative and having fine pores therein.

To polyethylene terephthalate of Example 1, 2.5% of sodium dodecylbenzenesulfonate was added after comple tion of the polymerization. Thus, there was obtained a polymer having an intrinsic viscosity of 0.655.

The so obtained polymer (A) was weighed at 295 C. by means of a gear pump and fed to a kneading screw portion heated at 285 C. Polystyrene (B) (*Styron 666, product of Asahi Dow Chemical Industry Co.) was weighed at 180 C. by means of a gear pump and fed to the kneading screw portion heated at 285 C. The mixing ratio of (A) to ('B) was 90:10.

Thereafter, the spinning, drawing, processing and knit- I ting were conducted in the same manner as in Example 1, and then the polystyrene Was eluted with trichlene at its boiling point. The weight decrease ratio was 9.1% at this treatment. It was confirmed that the filaments after the elution treatment contained sodium dodecylbenzenesulfonate in an amount of 1.0%. Thus, it is seen that the polystyrene portion incompatible with the polyester had been eluted out from the filaments and there were contained fine pored in the filaments. The water-absorbing property of the so treated filaments was characterized by 3 minutes before washing, more than 10 minutes after 10 Prior to the initiation of the preparation of polyethylene terephthal'ate, polyethylene glycol having a molecular weight of 20,000 was added to the polymerization system in an amount of 3.1% by weight based on the resulting polymer, and 2.5% by weight of sodium dodecylbenzenesulfonate was added after completion of the polymerization. Thus, there was obtained a polymer having an intrinsic viscosity of 0.663. In the same manner as in Comparative Example 6, the polymer was blend-spun with polystyrene, drawn, processed, knitted. and treated with trichlene. After the trichlene treatment the amount incorporated of polyethylene glycol was 3.0%, and the amount incorporated of sodium dodecylbenzenesulfonate was 1.0%. The polystyrene in an amount of 9.0% was eluted out and fine pores were formed. 7

The water-absorbing property of the product was characterized by 1.0 second after washings.

EXAMPLES 4 TO 7 AND COMPARATIVE EXAMPLES 7 TO 8 These examples are given to show what changes are brought about when the class of the polyalkylene ether to be incorporated is varied.

The experiments were conducted in the same manner as in Example 1 except'changing the class of the polyalkylene ether to be incorporated. The results of the experiments are shown in Table 6 below.

TAB LE 6 Comparative Comparative Example 4 Example 7 Example 5 Example 6 Example 8 Example 7 Class of polyalkylene Polypropyl- Polyethylene Poly hylene Ethylene Polyethylene Polyethylene lene glyco. glycol. glycol. oxide/proglycol. glycol! pylene oxide copolymer 3 Properties of processed yarn:

Strength (g./d.) 4-6 4.0... 4.3.... 4.6 4.3 4. 4.

Elongation (percent)-. 30.1.... 32.2.-.. 2

CR value (percent) 29.8..-. 31.0.--. 2 After alkali treatment:

Weight decrease ratio (percent) 7. 8"-.. 8. 0 8. 0

Aiziount t)incorporated of polyalkylene ether 1. 0 4. R 2. 3. 1. 1

percen Amount incorporated of sodium dodecylbenzene- 1.2 1.1 1. 0... 1.3

suionate (percent).

Water-absorping property:

Before washing LeSS than a 2 minutes.-- LeSS than 1 Less than 1 5 seconds Less than 1 second. second. second. second. After 10 washings. .J More than 10.. 7 seconds do More than 10 Do.

minutes. minutes.

Alter 50 washings... 1 second ..rl n 5 seconds.

Heailz resistance after alkali treatment (change in b +2. 5 +3. 0 +2. 5 +2. 0 +2. 0 +1. 9.

ya no 1 Having a molecular weight of 6,000. 2 Having a molecular weight of 600. 3 Having a molecular weight of 21,000 (copolyrnerization ratio =1:l)

4 Both terminal ends of which are blocked WlthOCH3 (molecular weight=16,000). 5 One terminal end of which is blocked with phosphoric acid (molecular weight =10,000).

washings and more than 10 minutes after 50 washings. The water-absorbing property of a knitted product of the filaments prepared without addition of polystyrene by conducting the spinning, drawing, processing and knitting in the same manner as above was characterized by more tha. 10 minutes before washing. The water-absorbing property of a knitted product obtained by subjecting the above mentioned knitted product to an alkali treatment with a weight decrease ratio of 6.1% was characterized by,3 minutes before washing and more than 10 minutes after 10 washings. In this alkali-treated knitted product the content of sodium dodecylbenzenesulfonate was 1.0%, and fine pores were not formed in the filaments because sodium dodecylbenzenesulfonate was compatible with the polyester.

EXAMPLE 3 This example is given to show that even when fine pores are formed by a method dificrent from the method adopted in Example 1, the effects of the present invention can be fully achieved.

EXAMPLES 8 AND 9 These examples are given to shown what changes are brought about by varying the class of the alkali metal sulfonate derivative in Example 1.

The experiments were conducted in the same manner asin Example 1 except using other alkali metal sulfonate derivatives instead of sodium dodecylbenzenesulfonate.

The results are shown lIl Table 7 below.

TABLE 7 Example 8 Example!) Class of alkali metal sulfonate derivative Sodium nonyl- Potassium dodecylbenzenesultonate. benzenesulfonate.

Properties of processed yarn:

Strength (g./d.)- 4.2- 4.1.

Elongation (percent) 34.2-. 33.6

GB value (percent) 36.0-. 34.8 Alter alkali treatment:

Weight decrease ratio (percent) 8.3- 8,5,

Amount incorporated of polyethylene glycol (percent) 1.6 1.3.

Amount incorporated oi alkali metal sulfonate derivative 1.0 0.9. w t (pgrcetnt). t

a er-a sor in to or Before wasliiiig. y Less than 1 second- Less than 1 second.

10 wash do 0.

50 washin do 1 second.

Heat resistance (change in b value) EXAMPLES 12 TO 13 AND COMPARATIVE EXAMPLES 11 TO 15 Frictional electrification voltages of various knitted products were measured at C. and a relative humidity of 43% by means of a rotary static tester. The results are shown in Table 9.

EXAMPLES 10 TO 11 AND COMPARATIVE EXAMPLES 9 TO 10 These examples are given to show what changes are brought about by varying the mixing method of polyethylene glycol (X) and sodium dodecylbenzenesulfonate (Y) in Example 1.

TABLE 9 Frictional electrification Sample voltage (v.)

Example 12 Knitted product of Example 1 2,300 Comparative Example 11-.. Knitted product of the control described in Example 1. 9, 800 Comparative Example 12.-. Knitted product of Comparative Example 2 7, 000 Comparative Example 13..- Knitted product of Comparative Example 3. 6, 500 Example 13 Knitted product of Example 2 2,100 Comparative Example 14... Knitted product of Comparative Example 5. 3, 100

Comparative Example 15- Knitted product obtained by conducting the the incorporation of polystyrene in Comparative Ex. 6. 7, 200

In these examples the amounts mixed of (X) and (Y) It is seen that the results given in Table 9 clearly are the same as in Example 1. The drawn yarns were of 0 demonstrate the eifects attained by the present invention. 75 deniers and 36 filaments. The spinning and drawing EXAMPLE 14 AND COMPARATIVE conditions were made as equal to those of Example 1 as EXAMPLES 16 T0 13 P The PIOCeFSmg kmttmg and alkah treatmeflt These examples are given to show the correspondence 601141110118 were qulte the Same as those of the water-absorption time used as the criterion for Example 1. evaluation of the water-absorbing property to the study The results are shown in Table 8 below. uncomfortable feeling of wearers.

TAB LE 8 Comparative Comparative Example 10 Example 11 Example 9 Example 10 Mi i th d (Y) was added to the (X) and (Y) were (X) was added to (X) was added to the polymerization vesadded to the the polymerizapolymerization vessel and mixed wlth polymerization tion, and (Y) was sel before polym- (X) by extruder, vessel atter incorporated by erization, and (Y) followed by polymerization. extruder. was added to the spmmng. vessel after polymerization. Properties of processed yarn:

Streng 4.4- 4.3- 4.4- 4.2. Elongation (percent). 1- 32.3- 31.6- 32.6. GB value (percent)- 4-3 35-6- 32.6. 36.2. After alkali treatment:

Weight decrease ratio (percent)- 8.2- 7.3. 6.9. Amount incorporated of polyeth lene glycol (percent). 1.7.. 1.5- 4.8 4.9. Amount incorporated of sodium dodecylbenzene- 1.2- 1.3- 1.1 1.3.

sulfonate (percent). Water-absorbing property:

Before washing Less han 1 5600116...- Less than 1 second. 3 minutes 4 minutes. 10 washings I 1 second More than 10 More than 10 minutes.

minutes. washings 1 second. 10 seconds do- Do. Heat resistance (change in b value). +1.7. +1.9- +2.3. +2.6.

In comparative examples, since (X) was copolymerized with the polyester and hence (X) was not selectively eluted at the alkali treatment, fine pores were not formed and filaments having a water-absorbing property could not be obtained.

With respect to each of a knit underwear of the product of Example 1, a knit underwear of the control product described in Example 1, a knit underwear of Comparative Example 2, and a commercially available knit underwear of pure cotton having a weight of 17X 10 g./cm. treatment, the weight decrease, the amount of polyethyl- 10 men having an age of 20 to 25 years put on such knit ene glycol and the amount of disodium nonylbenzeneunderwear and were allowed to stay for 3 hours at a room phosphonate were measured. The results are shown in maintained constantly at 27 C. and a relative humidity Table 11 below.

TABLE 11 Amount of Weight Amount of disodiinn decrease polyethylnonylbenzeneratio, ene glycol, phosphonate, percent percent percent Comparative Example 19 (before alkali treatment 5.0 2. 4 Example 15 (after alkali treatment) 8. 2 1. 9 1. 0

of 65%, and the number of men complaining of a stuffy Optical microscopic photos illustrating the sides of uncomfortable feeling was recorded. The tests were con- 15 the drawn yarn before the scouring and alkali treatments ducted with respect to either the underwears before washand of the drawn yarn after the scouring and alkali treating or the underwears after 50 washings. The results are ments were shown in FIGS. 5 and 6. FIG. 7 is an electroshown in Table 10. microscopic photo of the yarn of FIG. 5, after it has been TABLE 10 Number of men complaining of stuffy uncomfortable feeling Before After 50 Sample washing washings Example 14 Underwear of the product of Example 1 1 1 Comparative Example 16.-- Underwear of the control product described in Example 1- 9 0 Comparative Example 17-.- Underwear of the product of Comparative Example 2..- 2 8 Comparative Example 18... Underwear of pure cotton 1 1 EXAMPLE AND COMPARATIVE dyed with osmium tetraoxide and dissolved. FIG. 8 is an EXAMPLE 19' electromicroscopic photo of the yarn of FIG. 6, after it has been dyed with osmium tetraoxide and dissolved. Polyethylene terephthalate (A) of an intrinsic viscosity of 0.660 containing 0.5% of titanium oxide as a deluster- ,From the reu1ts glven Table FIGS- 5 to 3, ing agent and obtained by a customary method was it is seen that in the yarn before the alkali treatment the t 0 b means of a ear um and than polyethylene glycol was incorporated in the form of t' l t line ading scrgw portion heafed M 328? C. A 2:1 stripes. and that a Part of the polyethylerte glycol cone mixture (B) of polyethylene glycol having a number aver spondmg to 3.1% of the total yarn was stripped 01f by the lb alkali treatment to form fine pores. It is also seen that in ggg fi gzgfiifi g gg s gg g o gf 5 1 22 1 addition to the polyethylene glycol and disodium nonylbenzenephosphonate the polyethylene terephthalate per k p 40 5.52%??? and fed to the eadmg screw men heated so was stripped off is an amount of 4.0% by the alkali The mixing ratio of (A) and (B) was 9:25:75 The treatment, and hence, the yarn was made thinner and the mixture was transferred from the kneading screw portion Pores were expanded F interior From 8 it to a Spinneret portion While being kept in the molten 18 observed that the diameter of the pore was about 0.1;1.

state. Then, the molten mixture was spun at a rate of 30 and t length-to'diamete'r ratio was greater than gJmm through a Spinneret having 36 nozzles f a 0.23 With respect to the knitted cloth of the yarn before the mm. diameter The extrudate was taken up at a rate f alkali treatment and the knitted cloth of the yarn after the 1000 m./min. to obtain undrawn filaments. Thereafter, alkali treatment, the Water-absorbing P p y Was measthe filaments were drawn at a draw ratio of 3.66 at a ured. The results are shown in Table 12 below.

TABLE 12 Before washing After 10 washings After washings Comparative Example 19 (before alkali treatment) Mgigsthan 10 min- Margsthan 10 min- Mglgsthan 10 min- Example 15 (after alkali treatment) Less than 1 s cond Less than 1 second.-. Less than 1 second,

speed of 400 m./min. by means of a hot pin heated at From the results shown in Table 12 it is seen that even 100 C, filaments containing polyethylene glycol and disodium The resulting drawn filaments were characterized by a nonylbenzenephosphonate cannot possess a water-absorbfineness of 74.8 d., a strength of 4.9 g./d., an elongation ing property unless they have fine pores therein. of 25.6% and a boiling water shrinkage of 12.1%. Two Table 13 shows the results of the measurement of the of the drawn filaments were gathered and then subjected heat resistance Of the knitted clothes Of the yarn before {0 a wooly-processing treatment at a yam feed rate of the alkali treatment and 0f the yarn after the alkali treat- 49.8 m./min., a take-up rate of 44.0 m./min. and a hot mentplate temperature of 205 C. with the use of a spindle T E 13 I rotating at 175,000 r.p.m. The so obtained wooly- Heat resistance processed yarn were characterized by a strength of 4.4 Example N05 111 b g./d., an elongation of 30.3% and a CR value (crimp comparatlve p 19 (before 3114811 t tretaining property) of 34.8%. A knitted cloth having a meIlt) +2.0 weight of 15-l8 10* g./cm. was prepared from the Example 15 (after alkali tmatmellt) above wooly-processed yarn, and it was scoured at 80 C. yFor comparison Sake properties of ordinary polyester for 20 minutes under ThC COIldItIODS of a cleanser of 2 fila t (control) prepared i h addition f poly. g/litel', Soda ash of 1 gJlItel and a bath of 11100- ethylene glycol and disodium nonylbenzenephosphonate Then, the scoured cloth was treated for 20 nunutes with a were amined. The spinning, drawing, wooly-proce'ssing, N aqueous Solution of Sodium hydroxide at the boiling knitting and alkali treatment were conducted in the same point of the solution. Before and after the said alkali manner as described above. The drawn yarn was char- 17 18 acterized by a fineness of 73.8 d., strength of 4.9 g./d., COMPARATIVE EXAMPLE 24 an elongation of 26.4% and a boiling water shrinkage of 11.5%. The wooly-processed yarn was characterized by a This example is given to Show that a m i t' water.

strength of an elongatlon of 328% and a CR absorbing property is not imparted to filaments containing value of 36.3%. The weight decrease ratio by the alkali treatment was 2.2% The water-absorbing property of the only dlwdlum nonylbenzenephosphonate filaments knitted cloth was as follows: tained by subjecting the above filaments to an alkali treat- TABLE 14 Before washing After washings After 50 washings iitfiiih fitfiithtfitf::::::::::::::::::::::::::::::::::: $3.325.iiiififfi-itififiifiiiifff??? i)??? The heat resistance expressed in terms of the change ment, and filaments containing disodium nonylbenzenein b value of the knitted cloth was +1.5 either before or 15 phosphonate and having fine pores therein. after the alkali treatment. To polyethylene terephthalate of Example 15, 2.5% of EXAMPLES 16 AND COMPARATIVE disodium nonylbenzenephosphonate was added after com- EXAMPLES 20 To 23 pletron of the polymerization. Thus, there was obtained a polymer having an intrinsic viscosity of 0.657. These examples are given to show what phenomena 20 The so obtained Polymer A was Weighed at 5 are brought about y changing the amounts incorporated by means of a gear pump and fed to a kneading screw of polyethylene glycol and disodium nonylbenzenephos- Portion mated at 5 Q Polystyrene (B) (Styron 666", Phonate h Polyester of product of Asahi Dow Chemical Industry Co). was

The experiments were conducted in the same manner as weighed at 1800 C. by means of a gear pump and fed to described in Example 15 except changing the mixing ratio o the kneading screw portion heated at 285 C. The mixing of polyethylene glycol and drsodrum nonylbenzenephos ratio of to was 90:10.

honate, the incor oration ratio of the mixture of poly- I Ethylene glycol an fi disodium nonylbenzenephosphonate Thereafter the f drawing, processllfg and knitto polyethylene terephthalate, or the amounts of polyethtmg were conducted the Same manner f Pl ylene glycol and disodium nonylbenzenephosphontae in- 30 and then the Polystyrene was eluted Wlth trlchlene at corporated in the polyester. The results are shown in its boiling p The Weight decrease ratio Was 9.0%

Tabl 15 below, at this elution treatment. It was confirmed that the fila- TABLE 15 Comparative Comparative Comparative Comparative Example 20 Example 21 Example 16 Example 22 Example 23 Amount incorporated of polyethylene glycol (percent)-.. 5.0-. 15.0 5.0... 5.0..... 1.0. Amount incorporated of disodium nonylbenzenephosphate (percent)-. 0 0 5.0.. 10.0.. 1.0. Properties of wooly-processed yarn:

Strength (g. d.)- 4.4--- 40--- 4.3--. 37- 4.5.

Elongation percent) 31.3 29-2 32.0 28.1.........-. 33.2.

GB. value (percent) 30.3. 21.0- 31.0.- 17 5 33.8. After alkali treatment:

Weight decrease ratio (percent I 72.. 153.. 11.3- 10.8. 6.1;

Amount of polyethylene glycol (percent) 2.3-- 5.4..- 2.0.. 1.6.. 1.0.

Amount of disodium nonylbenzcnephosphate (percent). 0- 0 2.3.. 4.3.. 1.0. Water-absorbing property:

Before washing.-. Y Less thanl Less than 1 Less than 1 Less than 1 2minutes.

second. second. second. second. After 10 washings 1 second......' 1 second do do More than 10 minutes.

After washings- 6minutes.- 4mim1tes do do Do.

Heat resistance (change inb value) +1.8 +3.8 +2.2 +7.8 +1.7.

From the results shown in Table 15, the following ments after the elution treatment contained disodium nonmatters can be een: ylbenzenephosphonate in an amount of 1.0%. Thus, it is As in the case of Comparative Example 20, the filaseen that the polystyrene portion incompatible with the ments containing polyethylene glycol and having pores polyester had been eluted out from the filaments and there therein but being free of disodium nonylbenzenephoswere contained fine pores in the filaments. The waterphate are inferior in washing resistance of the water-ababsorbing pr p y of e 80 eated filaments was charsorbing property. As in the case of Comparative Example acterized by 4 minutes before washing, more than 10 min- 21, even if the amount of polyethylene glycol is increased Utes {liter 10 washings and {Bore than 10 minu es after 50 in Comparative Example 20, the washing resistance of the washmg The watef-abserbmg P p y of a khltted P water-absorbing property is not improved, and moreover llet 0f the filaments Prepared Without addition of P ythe heat resistance and the CR value of the processed Styrene y conducting the p i g drawing. Ploeessing yam are l d A i t case of Comparative E and knitting in the same manner as above was characterple 22, in case the amount of disodium nonylbenzeneiZed y more than 10 minutes before a h The Waterphosphonate is too large, the CR value of the processed absorbing P p of a knitting Product Obtained y yarn is low and the heat resistance is degraded. As in the lecting the ebove mentioned knitted pl'duet to an alkali case of Comparative Example 23 even if filaments com treatment with a weight decrease ratlo of 6.1% was chartain polyethylene glycol and disodium nonylbenzenephosacterlzed by 4 mmutes ,before was hmg f more thal} 10 phonate and the weight decrease is observed after the alg i x gp z'. In thls i lfimtted kali treatment, a sufiicient water-absorbing property is not as; f$ g ig g gz g iii g g ifi gfiz imparted the filaments. when the Welght decrease 18 due because disodium nonylbenzenephosphonate was compatonly to the surface falling and the polyethylene glycol ible withthe polyester contained in the form of stripes inside the filaments is not extracted. Thus, it is seen that the results given in Table EXAMPLE 17 15 demonstrate clearly the effects of the present iIlVCll- This example is given to how that even when fine tion. pores are formed by a method different from the method 19 20 adopted in Example 15, the eifects of the present inven- From the results shown in Table 16, the following tion can be fully achieved. matters can be seen:

Prior to the initiation of the preparation of polyethylene i Comparative Example 25, since the polyethylene p i Polyethylene glycol having a molecular glycol was not selectively eluted and fine pores were not Weight of 20,000 was added Polymerization System formed in the filaments, they do not exhibit a sufiicient an iilmount of 31% by Welght and 25% Welght water-absorbing property. In Comparative Example 26, of soduim .Stearate was added aftel: completlon of since the content of the polyalkylene ether in the filapolymenz-ano-n' there was obtained polymer havuig ments was too small the filament do n t exhbit suffian intrinsic viscosity of 0.663. In the same manner as in S 1 a clent water-absorbing property. Thus, it 1s seen that the Comparative Example 24 the polymer was blend-spun with polystyrene, drawn processed, knitted and treated with results given in Table 16 demonstrate clearly the effects trichiene. After the trichlene treatment the amount incorattained y the Present inventionporated of polyethylene glycol was 2.9%, and the amount incorporated of sodium stearate was 1.1%. The poly- EXAMPLES 22 TO 24 styrene in an amount of 9.0% was eluted out and fine pores were formed in the filaments. These examples are given to show what changes are The water-absorblng P p y offlle Preduet was eharbrought about by varying the class of the metal salt acterized by 8 seconds after 50 washings. derivative in Example EXAMPLES 18 TO 21 AND COMPARATIVE The experiments were conducted in the same manner EXAMPLES 5 0 26 as in Example 15 except using other metal salt derivative These examples are given to show what changes are instead of disedillm nenylbenzenephosphonatebrought about when the class of the polyalkylene ether to The results are shown in Table 17 below.

TABLE 17 Example 22 Example 23 Example 24 Class of metal salt derivative Sodium dodecyl- Potassium stearate-- Manganese nonylsulfinate. benzene phosphonate.

Properties of processed yarn:

Strength Elongation (percent) 0 R value (percent) After alkali treatment:

Weight decrease ratio (percent) Amount incorporated of polyethylene glycol (percent) Amount incorporated 0! metal salt derivative (percen Water absorbing property- Before washing. After 10 washing Do. After 50 washing 4 seconds. Heat resistance after alkali treatment (change in b value) +2.1 +2.2 .4.

be incorporated is varied in Example 15. EXAMPLES 25 TO 26 AND COMPARATIVE The experiments were conducted in the same manner EXAMPLES 27 TO 31 as in Example 15 except changing the class of the polyalkylene ether to be incorporated. The results are shown 'Frlctwnal electrlficatlon voltages o n us knitted in Table 16 below. products were measured at 20 C. and a relative humidity TABLE 16 Comparative Comparative Example 18 Example 25 Example 19 Example 20 Example 26 Example 21 Class of polyalkylene ether Polypropyl- Polyethylene Polyethylene Ethylene Polyethylene Polyethylene cne glycolJ glycolfl glycol. oxide/proglycol. glycol.

pylene oxide copolymori Property of processed yarn:

Strength (g /d) 4.5 4.1:

Elongation (percent) CR value (percent) Alter alkali treatment:

Weight decrease ratio (percent) 7 Amount incorporated 0t polyalkylene ether (percent).

Amount incorporated of disodium nonylbenxenephosphonate (percent).

' Water absorbing property:

Before washing Less than 3 minutes... Less than Less than 4 seconds Less than 1 second. 1 second. 1 second. 1 second. After 10 washings 1o More thtan l0 1 second do 4 m.lnutes Do.

mmu cs. After 50 washings 1 Se fl 8 secon do More than 10 3 seconds.

minutes. Heaat1 resistance aiter alkali treatment (change in b +2.8 +2.9 +211 +2.1 +2.0 +2.0.

v ue

! Having a molecular weight of 6,000.

2 Having a molecular weight of 600.

3 Having a molecular weight of 21,000 (copolymerization ratio:1=1).

4 Both terminal ends of which are blocked with-OCH; (molecular weight=16,000).

B One terminal end of which is blocked with phosphoric acid (molecular weight-:10,000);

of 43% by means of a rotary static tester. The results are shown in Table 18 below.

22 of 1000 m./min. to obtain undrawn filaments. Thereafter, the filaments were drawn at a draw ratio of 3.66 at a TABLE 18 Frictional electrification Sample voltage (v.)

Example 25 Knitted product of Example 2, 000 Comparative Example 27. Knitted product of the control described in Example 15 10, 000 Comparative Example 28.. Knitted product of Comparative Example 20- 6, 800 Comparative Example 29--- Knitted product of Comparative Example 21- 7, 000 Example 26 Knitted product of Example 16 2, 200 Comparative Example 30..- Knitted product of Comparative Example 23- 8, 500 Comparative Example 31--- Knitted product obtained by conducting the eluting treatment 7,200

after the incorporation of polystyrene in Comparative Ex. 24.

It is seen that the results given in Table 18 clearly demonstrate the effects attained by the present invention.

EXAMPLE 27 AND COMPARATIVE EXAMPLES 32 TO 34 These examples are given to show the correspondence of the water-absorbing, time used as the criterion for evaluation of the water-absorbing property to the stuffy uncomfortable feeling of wearers.

With respect to each of a knit underwear of the product of Example 15, a knit underwear of the control products described in Example 15, a knit underwear of the product of Comparative Example 20, and a commercially available knit underwear of pure cotton having a weight of l7 l0- g./cm. 10 men having an age of 20 to 25 years put on such knit underwear and were allowed to stay for 3 hours at a room maintained constantly at 27 C. and a relative humidity of 65%, and the number of men complaining of a stuffy uncomfortable feeling was recorded. The tests were conducted with respect to either the underwears before washing or the underwears after speed of 400 m./min. by means of a hot pin heated at 100 C.

The resulting drawn filaments were characterized by a fineness of 74.7 d., a strength of 4.9 g./d., an elongation of 28.1% and a boiling water shrinkage of 13.1%. Two of the drawn filaments were gathered and then subjected to a wooly-processing treatment at a yarn feed rate of 49.8 m./min., a take-up rate of 4.40 m./min. and a hot plate temperature of 205 C. with the use of a spindle rotating at 175,000 r.p.m. The so obtained wooly-processed yarn were characterized by a strength of 4.4 g./d., an elongation of 30.3%, and a CR value (crimp retaining property) of 34.8%. A knitted cloth having a weight of 15l8 10-- g./cm. was prepared from the above wooly-processed yarn, and it was scoured at 80 C. for 20 minutes under the conditions of a cleanser of 2 g./ liter, soda ash of 1 g./liter and a bath ratio of 1:100. Then, the scoured cloth was treated for 20 minutes with a 0.3 N aqueous solution of sodium hydroxide at the boiling washings. The results are shown 111 Table 19. point of the solution.

TAB LE 19 Number of men complaining of stufiy uncomfortable feeling Before After 50 Sample washing washings Example 27 Underwear of the product of Example 15 1 1 Comparative Example 32 Underwear of the control described in Example 15 9 9 Comparative Example 33... Underwear of the product of Comparative Example 20... 3 8 Comparative Example 34-.. Underwear of pure cotton 1 1 EXAMPLE 28 AND COMPARATIVE EXAMPLE 35 Polyethylene terephthalate (A) of an intrinsic vis- 50 cosity of 0.660 containing 0.5% of titanium oxide as a delustering agent and obtained by a customary method Before and after the said alkali treatment, the weight decrease ratio, the amont of polyethylene glycol and the amount of disodium nonylphenolphosphoric acid ester were measured. The results are shown in Table 20 below.

was weighed at 295 C. by means of a gear pump, and then fed to a kneading screw portion heated at 285 C. A 2:1 mixture (B) of polyethylene glycol having a number average molecular weight of 20,000 and disodium nonylphenolphosphoric acid ester was weighed at 85 C. by means of a gear pump, and then fed to the kneading screw portion heated at 285 C.

The mixing ratio of (A) and (B) was 92.5:7.5. The mixture was transferred from the kneading screw portion to a spinneret portion while being kept in the molten state. Then, the molten mixture was spun at a rate of 30 g./min. through a spinneret having 36 nozzles of a Optical microscopic photos illustrating the sides of the drawn yarn before the scouring and alkali treatments and of the drawn yarn after the scouring and alkali treatments were shown in FIGS. 9 and 10. FIG. 11 is an electromicroscopic photo of FIG. 9, after it has been dyed with osmium tetraoxide and dissolved. FIG. 12 is an electromicroscopic photo of the yarn of FIG. 10, after it has been dyed with osmium tetraoxide and dissolved.

From the results given in Table 20, and FIGS. 9 to 12, it is seen that in the yarn before the alkali treatment the polyethylene glycol was incorporated in the form of stripes and that a part of the polyethylene glycol corre- 0.23 mm. diameter. The extrudate was taken up at a rate sponding to 3.2% of the total yarn was stripped off by the 23 24 alkali treatment to form fine pores. It is also seen that in EXAMPLE 29 AND COMPARATIVE EXAMPLES addition to the polyethylene glycol and disodium nonyl- 36 TO 39 phenolphosphoric acid ester, the polyethylene terephthalate per se was stripped off in an amount of 3.6% by the These examples were given to show what phenomena alkali treatment, and hence, the yarn was made thinner are brought about by changing the amounts incorporated and the pores were expanded from their interior. From of polyethylene glycol and disodium nonylphenolphos- FIG. 12, it is observed that the diameter of the pore was phon'c acid ester in the polyester of Example 28. about 0.1;. and the length-to-diameter ratio was greater The experiments were conducted in the same manner than 10. as in Example 28 except changing the mixing ratio of With respect to the knitted cloth of the yarn before polyethylene glycol and disodium nonylphenylphosphoric the alkali treatment and the knitted cloth of the yarn acid ester, the incorporation ratio of the mixture of polyafter the alkali treatment, the water-absorbing property ethylene glycol and disodium nonylphenylphosphoric was measured. The results are shown in Table 21 below. acid ester to polyethylene terephthalate or the amounts TABLE 21 Before washing After 10 washings After 50 washings Comparative Example (before alkali treatment) More than 10 minutes. More than 10 minutes. More than 10 minutes.

Example 28 (after alkalitreatment) Less than 1 second Less than 1 second... Less than 1 second.

From the results shown in Table 21 it is seen that even 20 or polyethylene glycol and disodium nonylphenylphosfilaments containing polyethylene glycol and disodium phoric acid ester incorporated in the polyester. The renonylphenylphosphoric acid ester cannot possess a watersults are shown in Table 24 below.

TABLE 24 Comparative Comparative Comparative Com arative Example 36 Example 37 Example 29 Example 38 Exan fple 39 Amount incorporated of polyethylene glycol (percent) 5.0 15.0 5.0 5.0 1.0. Aiznount gleorporated or disodium nonyiphenoiphosphorie acid ester 0 0 5.0 10.0 1.0.

percen Properties of processed yarn- Strength (g./d.) Elongation (percent) R value (percent) After alkali treatment:

Weight decrease ratio (percent) 7.2 10.1 10.5 10.2 6.0. Amount of polyethylene glycol (percent) 2.0 5.8 1.8 1.6 1.0. Amount of disodium nonylphenylphosphoric acid ester (percent). 0 0 2.2 4.3 1.0. Water absorbing property:

Before washing... Less than 1 Less than 1 Less than 1 Less than 1 2 minutes.

second. second. second. second. After 10 washings 1 second 1 second .do do More than 10 minutes. After 50 washings .4 minutes..- 4m1nutes ..do do Do. Heat resistance after alkali treatment (change inb value) +1 8 +3.0 +2.2 +8.1 +1.8.

absorbing property unless they have fine pores therein. From the results shown in Table 24, the following mat- Table 22 shows the results of the measurement of the ters can be seen: heat resistance of the knitted clothes of the yarn before As in the case of Comparative Example 3 6, the filathe alkali treatment and of the yarn after the alkali ments containing polyethylene glycol and having pores treatment. therein but being free of disodium nonylphenylphosphoric TABLE 22 acid ester are inferior in washing resistance of the water- Heat resistance absorbing property. As in the case of Comparative Ex- Example No: (change 1n b val-ue) ample 37, even if the amount of polyethylene glycol was Comparative Example 35 (before alkali increased in Comparative Example 36, the washing retreatment) +2.1 sistance of the water-absorbing property is not improved, Example 28 (after alkali treatment) +1.9 and moreover the heat resistance and the CR value of the processed yarn are lowered. As in the case of Com- For comparison sake, properties of ordinary polyester parative Example 38, in case the amount of disodium filaments (control) prepared without addition of polynonylphenylphosphoric acid ester is too large, the CR ethylene glycol and disodium nonylphenylphosphoric acid value of the processed yarn is low and the heat resistance ester were examined. The spinning, dra'wing, wooly-procis degraded. As in the case of Comparative Example 39, essing, knitting and alkali treatment were conducted in even if filaments contain polyethylene glycol and dithe same manner as described above. The drawn yarn sodium nonylphenylphosphoric acid ester and the weight was characterized by a fineness of 74.9 d., a strength of decrease is observed after the alkali treatment, a sufii- 4.7 g./d., an elongation of 27.5% and a boiling water cient water-absorbing property is not given to the filashrinikage of 12.0%. The wooly-processed yarn was merits when the weight decrease is due only to the surface characterized by a strength of 4.5 g./d., an elongation falling and the polyethylene glycol contained in the form of 33.5% and a CR value of 37.2%. The weight decrease of stripes inside the filaments is not extracted. Thus, it ratio by the alkali treatment was 2.2%. The water-abis seen that the results given in Table 24 demonstrate sorbing property of the knitted cloth was as follows. clearly the effects of the present invention.

TABLE 23 Before washing After 10 washings After 50 washings Before alkali treatment More than 10 minutes-.. More than 10 minures-.. More than 10 minutes. After alkali treatment 5 minutes do Do.

(The heat resistance expressed in terms of the change COMPARATIVE :EXAMPLE 40 in b value of the knitted cloth was either before example is given to how a Suff cient wateror after the alkali treatment. absorbing property is not imparted to filaments containing only disodium nonylphenylphosphoric acid ester, filaments obtained by subjecting the above filaments to an alkali treatment, and filaments containing disodium nonylphenylphosphoric acid ester and having fine pores 26 Prior to the initiation of the preparation of polyethylene terephthalate, polyethylene glycol having a molecular weight of 20,000 was added to the polymerization system in an amount of 3.1% by weight, and 2.5% by therein. weight of monopotassium di(dodecylalcohol)phospho' To polyethylene terephthalate of Example 28, 2.5% of rous acid ester was added after completion of the polymdisodium nonylphenylphosphoric acid ester was added erization. Thus, there was obtained a polymer having after completion of the polymerization. Thus, there was an intrinsic viscosity of 0.663. In the same manner as obtained a polymer having an intrinsic viscosity of 0.658. in Comparative Example 40 the polymer was blend-spun The so obtained polymer (A) was weighed at 295 C. With polystyrene, drawn, processed, knitted and treated by means of a gear pump and fed to a kneading screw with trichlene. After the trichlene treatment the amount portion heated at 285 C. Polystyrene (B) (Styron incorporated of polyethylene glycol was 3.1% and the 666, product of Asahi Dow Chemical Industry Co.) amount incorporated of monopotassium di(dodecylalcowas weighed at 130 C by means f a gear pump nd hol)phosphorous acid ester was 1.1%. The polystyrene fed to the kneading screw portion heated at 285 C. The m an amount of 9.1% was eluted out and fine pores mixing ratio of (A) to (B) was 90: 10. e e formed 1n the filaments.

Thereafter, the spinning, drawing, processing and The water-absorbing property of the product was charkrn'tting were conducted in the same manner as in Examacleflled by 9 seconds after 50 washings. ple 28, and then the polystyrene was eluted with trichlene v at its boiling point. The weight decrease ratio was 9.0% S fiE fiP SZy R at this elution treatment. It was confirmed that the fila- 1 p v I ments after the elution treatment contained disodium non- These examples are given to show what changes are lyphenylphosphoric acid ester in an amount of 1.1%. Thus brought about when the class of the polyalkylene ether it is seen that the polystyrene portion incompatible with to be incorporated is varied in Example 28. the polyester had been eluted out from the filaments, The experiments were conducted in the same manner and there were formed fine pores in the filaments. The as in Example 28 except changing the class of the polywater-absorbing property of the so treated filaments was alkylene ether to be incorporated. The results are shown characterized by 3 minutes before washing, more than in Table 25 below.

TABLE 25 Comparative Comparative Example 31 Example 41 Example 32 Example 33 Example 42 Example 34 Class of polyalkylene ether- Polypropyl- Polyethyl- Poly hyl- Ethylene Polyethyl- Polyethylene glycol. ene glycol. ene glycol. oxide/proene glycol. ene glycol.

pylene oxilde co- Properties of processed yarn: 90 met.

Strength .ld.) 4.4 4.0 4.3- 4.6. 4.5-. 4,4, Elongation (percent) 32-0 27.0 8-2- 32.3- 33.1. 28,2, CR value (percent) 31.0 23.0 27-8. 32.3 29.3 31,2, Alter alkali treatment:

Weight decrease ratio (percent) 7.6 7. 8.0- 7.8- 7.9. 7,3, Amolglt incorporated of polyalkylene ether (per- 1.0 4.9 2-3 1.3 0.2 1.3. Agd nn t incorporated of disodium nonylphenyl- 1.0. 1.2.. 1.1. 1.1 1.3 1.3

phosphorus acid ester (percent). Water absorbing property: 1

Before washing Less than 1 3minutes...-- Less than 1 Less than 1 5 seconds Less than 1 second. second. second. second. After 10 washings do More than 10 .do ..do..-....-- 5 minutes..... Do.

minutes After washings 1 Secon 9 "Ninth do More than 10 3 seconds, Heat resistance after alkali treatment (change in b +2.7- +2.8 +2.5. +2.2 +g i +2.0.

1 Having a molecular weight of 6,000. 2 Having a molecular weight of 600. 5 Having a molecular weight of 21,000 (copolymerlzation ratio=1:1).

4 Both terminal ends of which are blocked with 0CH (molecular weight=16,000). One terminal end of which is blicked with phosphoric acid (molecular weight=10,000).

10 minutes after 10 washings and more than 10 minutes after 50 washings. The water-absorbing property of a knitted product of the filaments prepared without addition of polystyrene by conducting the spinning, drawing, processing and knitting in the same manner as above was characterized by more than 10 minutes before washing. The water-absorbing property of a knitted product obtained by subjecting the above mentioned knitted product to an alkali treatment with a weight decrease ratio of 6.2% was characterized by 4 minutes before washing and more than 10 times after 10 washings. In this alkali-treated knitted product the content of disodium nonylphenylphosphoric acid ester was 1.5%, and fine pores were not present in the filaments because disodiumnonylphenylphosphoric acid ester was compatible with the polyester.

EXAMPLE 30 This example is given to show that even when fine pores are formed by a method dilferent from the method adopted in Example 28, the effects of the present invention can be fully achieved.

EXAMPLES 35 TO 37 These examples are given to show what changes are brought about by varying the class of the metal salt derivative of phosphoric or phosphorous acid in Example 28.

The experiments were conducted in the same manner as in Example 28 except using other metal salt derivative instead of disodium nonylphenylphosphoric acid ester. The results are shown in FIG. 14. In FIG. 14, curves a, The results are shown in Table 26 below. b and c show measurement results of the product of TABLE 26 Example 35 Example 36 Example 37 Class of metal salt derivative Monosodlum nonylphenyl- Manganese nonylphenol- Disodlum dodecylalcoholphosphoric acid ester. phosphoric acid ester. phosphoric acid ester.

Properties of processed yarn- Strengt g./d

C R value (percent)- After alkali treatment:

Weight decrease ratio (percent) 8.2 8.3 8.3. Amount incorporated of polyethylene glycol (percent) 1 4 Amount incorporated of metal salt derivative (percent).- Water absorbing property: Before washingggger washlings. o 0.

er was ngs -1 d. 5 Heat resistance after alkali treatment (change in I) value +2. 2??? 2??? EXAMPLES 38 TO 39 AND COMPARATIVE Example 1, the product of pure cotton and the product EXAM 3 T 47 of ordinary polyethylene terephthalate described in Ex- Frictional electrification voltages of various knitted 2Q ample respeetlvety- From 14 it is Seen that the products were measured at C. and a relative humidity Product of the Present ln'vel'ltlon exhlbits a y. of 43% by a rotary static tester. The results are shown Proved Water-absorbing P p y Over Product Of ordinary in Table 27 below. polyethylene terephthalate and the water-absorbing prop- TABLE 27 Frictional electrification Sample voltage (v.)

Example 38 Knitted product of Example 28 2, 200 Comparative Example 43- Knitted product of the control described in Example 28. 9. 700 Comparative Example 44.-- Knitted product of Comparative Example 36 7, 500 Comparative Example 45--. Knitted product of Comparative Example 37. 6, 800 Example 39 Knitted product of Example 29 2, 000 Comparative Example 46 Knitted product of Comparative Example.39 8,000 Comparative Example 47- Knitted product obtained by conducting the eluting treatment 7,500

after the incorporation of polystyrene in Comparative ExJAO.

It is seen that the results given in Table 27 clearly erty of the product of the present invention is comparable demonstrate the elfects attained by the present invention. to that of the product of pure cotton.

EXAMPLE AND COMPARATIVE EXAMPLES What clalmed 48 To 50 1. Polyester filaments having at least polyethylene terephthalate recurring units containing therein 0.45% These examples are glven to show the correspondence 40 by weight of a polyalkylene ether having a numb r averof the watel"absorbing time f as the criterion for age molecular weight exceeding 4,000 and having a main evahlatloll 0f the Yvater'flbsorhlhg P p to the stuffy chain consisting essentially of repeating alkylene ether uncomfortable feeling of h units and 0.33% by weight of a surface-active metal salt Wlth respect to each 9 a kmt underwear of the P derivative having at least one hydrophobic group of more of 'f 28, a kmt vnderwearpf the control Prod 45 than six carbon atoms, selected from metal salt derivatives described m Example knit underwear the of sulfonic acids, carboxylic acids, phosphonic acids, sulpmfluct of CPmPaatm Example and a CPmmemIfmY finic acids, phosphoric acids and phosphorous acids, said available knit underwear of pure cotton having a weight filaments having fine pores of a diameter of 0 of 17 10 g./c'm. 10 men having an age of 20 to 25 years put on such knit underwearv and were allowed .to 50 stay at a room maintained constantly at 27 C. and a relative humidity of and the number of men complaining of a stuffy uncomfortable feeling was recorded. The tests were conducted with respect to either the underwears before washing or after 50 washings. The re- 55 microns aligned in the direction of the filament axis, the ratio'of the pore volume to the filament volume being 05-10%.

2. The polyester filaments of claim 1 wherein said metal salt derivative is an alkali metal sulfonate derivative.

3. The polyester filaments of claim 1 wherein said metal sults are shown in Table 28. salt derivative is at least one member selected from the TABLE 28 Number of men complaining of stuffy uncomiortable feeling Before After 50 Sample washing washings Example 40 Underwear of the product of Example 28 1 1 Comparative Example 48 Ur2igierwear of the control product described in Example 9 9 Comparative Example 49 Underwear of the product of Comparative Example 36.- 2 8 Comparative Example 50. Underwear of pure cotton 1 1 EXAMPLE 41 group consisting of metal salt derivatives of carboxylic acid, phosphonic acid and sulfinic acid.

Each of a knitted product obtained in Example 1, an 4. Polyester filaments of claim 1 wherein said metal alkali-treated knitted product of ordinary polyethylene salt derivative is at least one member selected from the terephthalate processed yarn described as control in EX- group consisting of di-metal salts and mono-metal salts ample 1 and a commercially available knitted product deof phosphoric acid and phosphorous acid. scribedin Comparative Example 18 was washed 20 times. 5. The polyester filaments of claim 1 wherein said poly- Then water-absorbing properties of these products were alkylene ether is present in an amount of from 14% by examined by employing the apparatus shown in FIG. 13. weight.

6. The polyester filaments of claim 1 wherein said metal salt derivative is present in an amount of from 0.3- 2.5% by weight.

7. The polyester filaments of claim 2 wherein said alkali metal sulfonate derivative has one sulfom'c group and a hydrophobic group in addition thereto.

8. The polyester filaments of claim 3 wherein said metal salt derivative has at least one hydrophilic group and hydrophobic group.

9. The polyester filaments of claim 4 wherein the remaining hydroxy groups of said di-metal salts and monometal salts of phosphoric acid and phosphorus acid are in the form of alkylaryl esters.

SAMUEL H. BLECH, Primary Examiner M. FOELAK, Assistant Examiner US. Cl. X.R.

2'602.5 M, 2.5 E, 860, 873; 264-49, 210 F, 290T 

